Hallums DP1, Gomez R1, Doyle AP2, Viet CT4,5, Schmidt BL4,5 and Jeske NA1,2,3*
1Departments of Oral and Maxillofacial Surgery, University of Texas Health Science Center at San Antonio, USA
2Departments of Pharmacology, University of Texas Health Science Center at San Antonio, USA
3Departments of Physiology, University of Texas Health Science Center at San Antonio, USA
4Department of Oral Maxillofacial Surgery, New York University, USA
5Department of Oral Maxillofacial Surgery, Bluestone Center for Clinical Research, New York University, USA
Raf Kinase Inhibitory Protein (RKIP) expression has been profiled for a number of unique tissue cancers. However, certain tissues have not been explored, and oral and oropharyngeal cancers stand out as high priority targets, given their relatively high incidence, high morbidity rate, and in many cases, preventable nature. The purpose of this study was to examine changes in RKIP expression and phosphorylation in tissues resected from oral cancer patients, and compare to results generated from immortalized cell lines raised from primary oral cancer tissues, including oral squamous cell carcinoma line 4 (SCC4) and human squamous cell carcinoma line 3 (HSC3). Out of 4 human samples collected from male and female patients across various ages with variable risk factors, we observed an across the board reduction in RKIP expression. Two human samples demonstrated a significant increase in phosphorylated RKIP when normalized to total RKIP, however all 4 were increased when normalized to total cellular protein. The immortalized oral cancer cell culture HSC3 revealed significant increases in phosphorylated RKIP with no change in total RKIP expression, while line SCC4 demonstrated an increase in both total and phosphorylated RKIP. Results presented here indicate that oral cancers behave similarly to other cancers in terms of changes in RKIP expression and phosphorylation, although immortalized cell line expression profiles significantly differ from human tissue biopsies.
Oral cancers; Raf kinase; Phosphorylation
Hallums DP, Gomez R, Doyle AP, Viet CT, Schmidt BL, Jeske NA. RAF Kinase Inhibitory Protein Expression and Phosphorylation Profiles in Oral Cancers. Clin Surg. 2016; 1: 1100.